1. Field of the Invention
The present invention pertains to weight resistance exercise machines. More particularly, the present invention pertains to an exercise assembly having a multi-cable and pulley linkage system attached to a single load such as a weight stack, or other resistance means (including, without limitation, pneumatic, hydraulic or electromagnetic) and attached to a biofeedback system.
2. Brief Description of the Prior Art
It is well established that many people have some level of imbalanced strength in their limbs. In other words, limbs on one side of a person's body are usually stronger than limbs on the other side of the body. This common phenomenon frequently results in a person's body being divided into a dominant (strong) side and a non-dominant (weak) side of the body.
Such imbalanced strength can result in a condition known as “bilateral deficit.” As used herein, the term “bilateral deficit” refers to a condition in which the total force produced by two limbs (for example, left and right arms) is less than the sum of the forces produced by such limbs acting alone. By contrast, the term “bilateral facilitation” is when the total force produced by both left and right limbs is greater than the sum of the forces produced by such limbs acting alone.
When a person uses only one limb to perform a physical task (for example, lifting a weight, or throwing or kicking a ball), the person typically uses his or her dominant side, because the dominant side is stronger, more efficient and feels more natural to use. When a person performs a physical task using both limbs (such as, for example, lifting a weight or an object using both arms simultaneously), the person typically tends to lead and lift more with limb(s) on the dominant side of the body; hence the expressions—“right side dominant” or “left side dominant”.
Conventional exercise machines do not take such imbalance into account. Such conventional exercise machines typically have a support frame and a load (frequently comprising a weight stack or some other resistance means) mounted on or near said frame. A linkage system, usually comprising a cable and pulley system or movement arms, enable a user to lift said load when performing specific resistance exercise movements. In many cases, such exercise machines can be used for bilateral exercise—that is, exercise in which both limbs (arms or legs) are used simultaneously. However, cable and pulley linkage systems of conventional exercise machines do not allow for a determination of how much each limb (whether arm or leg) is contributing to the overall effort when weight is lifted during bilateral exercise performance.
Moreover, with conventional resistance exercise machines, weight is typically lifted in a predetermined, linear fashion using guide rods or movement arms that create a fixed exercise motion. There is no balance involved during this type of exercise. Such fixed motion frequently produces “linear strength” as dictated by the machine. However, the human body generally does not function in a purely linear manner during normal physical activity. Muscles do not work in isolation, but rather in an integrated and balanced team effort.
Conventional linear guided exercise machines, which provide for fixed motion during exercise performance, limit the development of balanced strength. No internal correction is needed to perform the movements and virtually no external feedback is given to a user with regard to symmetry of force production. Lifting a weight that requires a user to balance both sides during bilateral exercise improves balanced strength and thereby delivers better training results.
Such muscular imbalance, which is not addressed by conventional exercise equipment, is an important factor to consider for injury prevention, physical performance and/or for therapy used to recover from an existing injury. Conventional exercise equipment manufacturers have attempted to even out this muscle imbalance by adding a second load or weight stack into the equipment design—that is, one weight stack for each limb. This concept is frequently referred to as “unilateral training.” However, this solution does not address the fundamental issue of balanced bilateral training.
Another limitation of conventional exercise equipment is the lack of biofeedback. By using biofeedback information, a user's brain quickly learns how to control sensory-understandable interpretations, and this biofeedback loop trains the muscles involved to adapt to the training stimuli. The result is a self-regulatory process. As such, biofeedback can be an essential tool in exercise performance when enhanced body-mind link is promoted. Importantly, biofeedback training can also train a user's nervous system to “lead with the weak side” during bilateral exercise performance.
Thus, there is a need for a new and improved exercise assembly system for resistance-based training. Such exercise assembly should be simple in design and cost effective, while suitable for use in the prevention and rehabilitation of muscle and joint injuries. Further, such exercise equipment should help correct bilateral deficit during bilateral exercise performance; specifically, such exercise equipment should help correct muscle/strength imbalance between dominant and non-dominant limbs (arms or legs) during exercise (work) performance. Such exercise equipment should beneficially improve functional strength, while training a user's non-dominant limb(s) to become more efficient in contributing to work effort during bilateral exercise performance in order to make the contribution of effort more even between the two limbs.
Such exercise assembly should also beneficially provide biofeedback information that clearly indicates how much each limb is contributing to an overall work effort during bilateral exercise performance. Such biofeedback should train a user's neuromuscular system to contribute equally with both sides of the body during exercise performance and train a user's brain and nervous system to “lead with the weak side” during bilateral exercise performance.
Exercise speed, or speed of movement, is another important consideration in exercise equipment design. The load being lifted (as expressed in pounds, for example) represents a true weight while said load is at rest or when moving at a constant speed. However, once the load is in motion, the changes in speed movement can cause the actual weight resistance to change. This is especially noticeable during high speed training. These changes in force are affected by acceleration and/or deceleration of a load when the speed of movement changes. Thus, there is a need for a pulley system designed specifically for high speed training, by adding one or more additional wheels to the cable pulley configuration.